Q46. - Algebra 1

Question

Determine whether each set of measures can be the lengths of the sides of a right triangle.

12, 16, 21

Step-by-Step Solution

Answer

The given set of measures is not the lengths of the sides of a right triangle.

Step1. Given

The length of the triangle is $12,16,21 12,16,21$

Step2. Determine how to identify whether the given measures are the sides of the right triangle, acute triangle, an obtuse triangle.

If, $c$ is the longest side of the triangle, $a$ and $b$ are the other two sides of the triangle then:

(i) If $c^2<a^2+b^2$, then the triangle is acute.

(ii) If $c^2=a^2+b^2$, then the triangle is a right triangle.

(iii) If $c^2>a^2+b^2$, then the triangle is obtuse.

Step3. Determine whether the given set of measures can be the lengths of the sides of a right triangle.

The triangle is having sides of measures 12, 16, and 21.

The longest side of the triangle is 21.

Therefore, the $c$ value is 21.

Therefore, the values of $a$ and $b$ are 12 and 16 respectively.

Now, it can be obtained that:

$\begin{array}{l}{a}^2={12}^2=144\\ b^2={16}^2=256\\ c^2={21}^2=441\\ a^2+b^2=144+256=400\end{array}$ 

It can be noticed that:

$\begin{array}{l}{a}^2+b^2=400\\ a^2+b^2\ne c^2\end{array}$

As, $c^2\ne a^2+b^2$, therefore, the triangle is not a right triangle.

Therefore, the given set of measures is not the lengths of the sides of a right triangle.